Protected metal article and method of making the same



- June 7, 1932 A. w. coFFMAN 1,362,332

PROTECTED METAL ARTICLE AND METHOD oF MAKING THE sur:

Filed March 5, 1931 Patented June 7,v 1932 UNITED STATES PATENT OFFICE ALBEN W. COFFMAN, OF PITTSBURGH, PENNSYLVANIA, ASSGNOR T) E. ROBERT- SON COMPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION F PENNSYL- VANIA PROTECTED METAL ARTICLE AND Application led March 3,

yto provide a protected metal article of the .character referred to, which is capable ofi.

` resistingrelatively high temperatures and therefore capable of being used as a fire-resisting material for building purposes and also in other situations where itis exposed to heat. l

The invention also has for its object to produce the improved protected metal article in a novel manner as will be described.

To these ends. the steel or other metal member has the layer of fibrous material, preferably asbestos felt, wool felt, or the `l'ike affixed to one and preferably both surfaces b v a metallic adhesive, such as a'layer of tin, zinc, lead, cadmium, or similar metal or alloy of metals having a lower melting point than the steel and capable of being rendered sufficiently'fluid when heated to near its melting point to penetrate into andbond with the fibrous layer or layers, and thereby, when cooled, firmly affix the fibrous layer to the metal member to be protected.

The improved protected metal article may be produced by coating the metal article with a layer of the metallic adhesive, applying the felt or other fibrous vlayer tothe coated article and subjecting both to pressure and heat sufficiently high to enable the metallic coating to become sufficiently fluid to enable it to penetrate into .the fibrous layer under the influence of the pressure, after Awhich the product thus treated is allowed to cool, whereupon it will be-found that the felt or' other fibrous layer is firmly 'bonded or affixed to the steel o`r other metal member' to be protected.

These and other `features of this invention will be hereinafter described and particularly pointed out in the claims at the end of specification.

Fig. 1 is a lan viewof a protected metal sheet embodying this invention, with parte broken away, and

Fig. 2, a section of thefprotected metal METHOD 0F MLAKING THE SAME 1.931.l Serial No. 519,803.

sheet shown in Fig. l on an enlarged scale, the section being taken on the line 2-2.

Referring to the drawing, 10 represents the metal member to be protected, which member may be of steel or other metal and particularly of corrodible metal and is herein shown as a flat sheet, but which may be oother forms.

The metal member l0 will be hereinafter referred to as a steel sheet. .Y

The steel sheet 10 is provided with a coating or layer 12 of a metal of lower-melting point and preferably of the so-called noncorrodible metals.

The steel sheet l() may be coated with tin, zinc, lead, cadmium, bismuth or like metal or alloys of metals, and for simplification the coating metal will be hereinafter referred to as tin.

The coating or layer 12 of tin may be applied to the steel sheet 10 by dipping or passing thel steel sheet into or through a bath of melted tin as now cpmmonly practiced in the production of tin-coated steel sheets.

The tin-coated steel sheet in accordance with this invention is provided on `one and preferably on both sides with a protective layer 13 of asbestos felt, wool felt, or other fibrous material.

The layer of fibrous material 13 will be hereinafter referred to as the felt layer, which is applied to the tin-coated metal sheet 10 and subjected to heat and pressure, said heat being sufficient to cause 'the tin coating to assume a mobile condition, so that under the influence of pressure it may be forced into the interstices of the felt, and when the tin coating is cooled, portions thereof will be interlocked or keyed with the fibers of the felt andthe latter will be firmly affixed tothe steel sheet by a non-flammable metallic adhesive.

The improved protected steel sheet may be g produced by applying the felt layers to the steel sheet and mechanically clamping them' together between suitable plates so as' to eect intimate contact4 of the felt layerswith the tin coating, and when thus assembled, placingthem in an oven which 1s heated to a temperature sufficiently high to render the tin coating fluid or substantially huid., il temperature of 230" to 250 C. is sucient to render the tin coating effective as a metal adhesive, which, when cooled, Aiirmly axes the felt layer to the steel sheet.

By the method above described, it will be observed that the `ielt layer is subjected to pressure before the tin coating is heated but it is not desired to limit the invention to this method as the layers may be heated before the pressure is applied.

To this end, the felt layers are applied to the tin-coated steel sheet With the latter cold and Without being' subjected to pressurea but are merely properly positioned With relation to the tin-coated steel sheet, and the layers thus assembled are placed in an oven, which is heated to a temperature 'from 230 to 250 C. and when the tin coating is in an adhesive or substantially fluid condition, the assembled layers are removed from the oven and immediately passed through a set of cold rolls, which applies the pressure to the Ytelt layers-and also cools the tin coating.

It may and preferably will be preferred to employ this second method in the produc tion of protected metal sheets in dat form as 'they may be more expeditiously produced than by the first method, but it is not desired to limit the invention to the particular methods disclosed of subjecting the layers of felt and tin to heat and pressure.

llrom the above description, it Will be observed that the felt layers are aflixed to -the steel sheet or member by a metallic adhesive., which is ductil-e when cold and ca able of being bent without cracking7 is'unaected by atmospheric temperature changes, and has no objectionable coloring eect upon the enterior surface of the 'felt layers, so that when a felt layer of normally light or White color, such as asbestos felt, is used as the iibrous layer, the exterior surface oi" the protected metal sheet may be painted or have applied to it any desired color, either light or darli, and given any desired artistic appearance or design. i

So also, the felt layer may have applic to or incorporated with it protective substances such as bitumens, resins, plastics, and the like to meet any condition of use.

The metallic adhesive being ductile enables the protected metal sheet to be bent or corrugated Without cracking and exposure lBf the steel or other corrodible metal mem It will 'further be observed that the improved protected metal article and especieln ly the improved protected metal sheets hav ing asbestos felt layers and employed roofing and siding purposes in buildings ford superior protection against re, es such. sheets are non-dammable.

Y The improved metal article has been here- Lacasse in described as an improved protected metal sheet, but 1t is not desired to limrtthe 1nvention in this respect, as the invention may i., improved article of manufacture having a fibrous layer aihxed to a metal member by an interposed metallic adhesive.

2. in improved article oil manufacture having a felt layeraiiiaed to a steel member by an interposed metallic'- adhesive Which coats the metal member and penetrates into the felt layer.

.An improved article of manufacture having a librous layer axed to a corrodible metal member by a non-corrodible metal layer covering said metal member and pene'- tratine into said fibrous layec,

et. n improved article of manufacture having a iibrous layer lreyed to. a metal layer covering a metal member of a higher-melting point.

5. An improved article of manufacture having a :telt layer aflixed to a steel sheet by an interposed layer of non-corrodible metal which covers said steel sheet and is keyed to said felt layer.

6. An improved article oit manufacture having a brous layer affixed to a metal member by an interposed metallic layer of lowermelting point than said metal member.

i?. The method of producing a protected metal article having abrous layer axed to a metal member by an interposed metallic layer of lower-melting point than said metal member, which consists in applying the fibrons layer to the metal member covered with the metallic layer of lovver melting point and subjecting the parts thus assembled to heat and pressure.

8. The method of producing a protected metal article havin a brous layer axed to a metal member y anl interposed metallic layer ot lower-melting point than said metal member, Which consists in pressing the brous layer against the metallic layer or" lower-melting point while the latter is in a heated condition and substantially huid, and then allowing the substantially luid metal to cool.

lin testimony whereof, l have signed my name to this specicat-ion. v

ALBEN W. CUFFMAN.

12o i'A 

